Printers known as direct-to-object (DTO) printers have been developed for printing onto three-dimensional (3D) objects. FIG. 4A depicts a prior art printing system 100 configured to print the surface of an object 104 mounted to a holder 108 as the holder 108 moves on a member 116 past an array 112 of fixed printheads 118. As used in this document, the term “fixed printhead” refers to printheads in a printer that are immobile and their faceplates remain parallel with the plane of the object holder throughout the printing of the object secured by the holder. One or more of the printheads 118 in the array 112 ejects ultraviolet (UV) ink onto the object and the UV lamp 120 is operated by controller 124 to cure the UV ink. The printheads are arranged so the object passes the white printhead first, the cyan color printhead second, the black printhead third, and the magenta printhead fourth. Although the colors can be arranged in other sequences, white typically leads the other colors to provide a background for the other colors. The controller 124 is configured to operate the actuator 128 to move the holder 108 after the object is mounted into the holder. The holder 108 can also be configured with an actuator that the controller operates to rotate the object in the holder. A first sector of the circumference of the object is printed in a first pass by the printheads, cured by the UV lamp 120, rotated to present a different sector of the object as the holder passes the printheads so the new sector can be printed, and then the holder and object are returned to a position opposite the UV lamp 120 so the ink on the newly printed sector can be cured. Alternatively, a second UV lamp can be added below the cyan printhead to cure the UV ink ejected onto the object when the holder moves in the direction of the white printhead to the cyan printhead. Controller 124 is configured to operate the printheads in the array 112 to eject marking material onto the surface of the object 104 as the holder 108 and the object 104 pass the printheads. FIG. 4B depicts the holder 108 and the object 104 as they face the printhead array 112. Latches 132 attach the holder 108 to the member 116.
The architecture of the system 100 requires multiple passes by the printhead array 112 with the object being returned for curing by the UV lamp 120 after each pass so the UV ink can be dried before another pass is performed. Alternatively, an additional UV lamp is required and this addition necessitates additional expense. Moreover, the system 100 is limited to printing images on one object and the images are printed one sector at a time. Therefore, a direct-to-object printing system that enables many objects to be printed and cured with a single UV lamp would be beneficial.